Final answer:
A guardrail system is a safety barrier that prevents falls on worksites and is mandated by OSHA regulations for worker protection.
Step-by-step explanation:
A guardrail system is a barrier including a top rail and midrail, designed to prevent workers from falling to a lower level. This safety feature is part of the Occupational Safety and Health Administration's (OSHA) regulations that employers must comply with in order to ensure the safety and health of their workers.
Guardrail systems are among various other requirements, such as providing fall protection equipment, preventing trench cave-ins, limiting exposure to infectious diseases, and ensuring the safety of workers in confined spaces.